Precision fiber cutter



Feb- 25, 1957 R. D. HEFFELFINGER PRECISION FIBER CUTTER Filed Aug. B. 1955 United States Patent Office 2,782,853 Patented Feb. 26, 1957 annessa PRECISION FIBER CUTTER Robert D. Helleltlnger Lansdowne, Pn assigner to Amerlean Viscose Corpotiadon, Philadelphia, Ps., n corporation of Delaware Application August 8, 1955, Ser'ml No. 536,956

I9 Claims. (Cl. 164-y-68) My present invention relates to a precision fiber or liock cutter for producing accurate and uniform length ber or lloclt. In particular, to a liber or lloclt cutter wherein the clearance between the fiber cutting blades may be accurately and easily set before the cutter is put in operation and wherein the blade clearance may be controlled and maintained during cutter operation.

In general, fiber cutters which have been used hereto- -fore include a rotating cutter head having a plurality of -cutting blades mounted therein.

These rotatable blades cooperate with a stationary blade mounted adjacent the cutter head to cut or sheer olf bundles of continuous lilaments or bers fed to the blades into staple liber or flock material.

There has been expressed a great deal of dissatisfaction with this type ot cutter in view of the extensive amount of time and cEort required to properly initially set and maintain the desired clearance between the cutting edges of the rotating blades and the stationary blade. During the operation of the cutter, the cutter head expands because of a gradual increase in temperature of the cutter lhead as the cutting operation progresses. Such expansion -of the head, of course, gradually moves the cutting edges -of the rotating blades into a closer clearance with the cutting edge ot the stationary blade. Usually, with the above described cutter, the lirst indication that the operator has of the change of clearance between the rotating blades and the stationary blades i; when hc hears the opposing blades clashing. Such contact between the blades damages the cutting edges of the blades and the cutting operation must be suspended while the cutting edges of the blades are being reground or while the blades are replaced with properly ground blades.

With the above described cutters, the initial adjusting ot the blade clearance before the cutting operation is started, and any subsequent adjustments of thc blade clearance during the cutting operation to maintain the clearance, requires a repositioning of the blades within their mountings. Such repositioning usually requires the loosening and removal ol a great number of nuts, bolts and screws which support the blades in their mountings. Painstalting and tedious care must be exercised by the operator to maintain proper blade clearance while rc storing the bolts, screws and nuts in position. As mentioned above, when adjustment of the blade clearance is required after the cutter is in operation, the cutter must be shut down while making the adjustment.

It is thenelore a primary object of my invention to provide a novel and improved precision liber or flock cutter wherein the clearance between the rotating blades of the cutter head and the stationary blade may be easily set and accurately controlled and maintained during the cutting operation.

Another object of my invention is to provide in n precision liber or llock cutter novel and improved automatic means for continuously maintaining proper clearance between the stationary blade and the rotating blades of the ber cutter when the cutter is in operation.

Still a further object of my invention is to provide in a precision liber or Hock cutter means which will automatically maintain the preset clearance between the rotating blades und the stationary blade regardless of any non-uniformity in the length or dimensions of the cutting edge ol the blades across the blade width caused by the blade grinding operation.

A further object of my invention is to provide a novel and improved safely feature for the stationary blade for the cutter of the above objects whereby yarn jam ups between the blades may be easily and safely relieved.

Other objects and advantages of my invention will be come more apparent from a study of the iollowing dcscription and drawings wherein:

Figure I ls a side view partially sectioned of my precision liber cutter showing one embodiment ol the cutter;

Figure 2 is a detail showing still another embodiment of my invention;

Figure 3 is a view taken on the lines III, III of Hgure l; and

Figure 4 is a detail showing still another embodiment of my invention.

Brieliy, the precision liber cutter of my invention comprises a rotatable cutter head having at least one liber cutting blade mounted in the head. A stationary ber cutting blade is mounted adjacent the rotating head and cooperates with the blades of the head to cut or shear olf fibers or Hock material from a bundle of libere or lilaments which are supplied to the opposing blades by n feeding unit. A mounting ls provided for the stationary blade and a control unit cooperates with the stationery blade mounting whereby the clearance between the opposing blades may be easily set and controlled. Resilient means contact die stationary blade mounting and oppose the adjusting means to rmly hold the stationary blade mounting lirmly in place.

Referring now to the drawings, the preferred embodiments of my invention will now be described. As seen in Figure l there is provided a rotatable cutter head l mounted on a drive shaft 3. The cutter head l may be of any width desired. Mounted in the cutter head I and extending through the cutter head periphery are liber cutting blades 5. 5 which extend substantially the width of the head 1. A stationary blade 6 mounted adjacent the cutter head l and extending substantially the width ot the head cooperates with the rotating blades 5, 5 to cut or shear ott Iibers or llocl'. material from a bundle of continuous laments or libera B continuously fed to the stationary blade by a pair of cooperating endles belts 7. 7 mounted around driven rolls 8, 8 and plates 9. 9. It should be pointed out here that the continuous filament bundle is used when staple liber is to be produced by the cutter while the liock may be cut from either the staple liber or continuous filament bundles. A plurality of the bundles of the lilaments or libera B are gencrally fed in a side by side relationship through the feed belts 7, 7.

The above described features do not constitute pre se a part of my invention. My invention, as pointed out above, is concerned with the stationary cutting blade, its mounting and the means for setting, adjusting, con trolling and maintaining the clearance between the stationary blade and the rotating blades 5, 5 of the cutter head l. These features of my invention are contained -in various embodiments which will now be described.

As seen in Figure 2. the stationary blade 6 which extends thc width of the cutter head l is supported in a mounting 19 of substantially the same width as the blade 6 and which in turn is supported on a fixed shaft 22 also extending the width of the cutter head 1. The mounting t9 is capable of rotating about the shaft 22. A ledge extension or boss 25 of the mounting 19 extends laterally from and substantially the width of the mounting 19.

As further seen in Figure 2. a bracket 28 is uxed to the base stippen 30. The ledge extension of boss 2S of arcanes the blade mounting i9 is positioned between the upper and lower arms 32, 32' of the bracket 28. An adjusting screw 35 is threaded through the upper arm 32 to contact the top surface of the boss extension 2S. Lock nut J7 threaded over the adjusting screw 35 cooperates with the arm J2 to lock the adjusting screw in place. A spring 40 is compressed between the lower bracket arm 32 and the bottom surface of the ledge extension or boss 25 of the stationary blade mounting 19. The operator need only adjust the single adjusting screw 35 to rotate the stationary blade mounting 19 around the shaft 22 to move thc stationary blade 6 toward or away rorn the rotating blades 5. S to adjust and control the clearance between the rotating blades 5, and the stationary blade 6. To rotate the stationary blade mounting i9 in a counterclockwise direction, the operator merely raises the adjusting screw 35 and the spring 40 will urge the ledge extension in an upward direction until it contacts the end ofthe screw 3S. By lowering the adjusting screw 35. the stationary blade mounting may be rotated in a clockwise direction. Since constant pressure is being applied to the bottom surface of the boss 25 by the compressed spring 40, the stationary blade mounting 19 will be held firmly in place. As many` sets of brackets 28 with adjusting screws and opposing compressed springs may be provided as desired across the width of the ledge or boss 25 to provide further accuracy in setting, adjusting, controlling and maintaining the proper blade clearance.

By experimentation, the operator may prepare time -study charts showing a relationship between the operating time of the cutter and the progressive expansion of the cutter head brought about by progressively rising temperature of the cutter head due to continued operation of the cutter. With the chart as an aid, the operator may adjust the adjusting screw while the cutter is operating without interrupting the cutter operation to maintain the initial and desired set clearance between the rotating blades 5 and the stationary blade 6.

The use of the spring or springs also provides a safety feature in case of a jam of the liber or tilamenr bundle between one of the blades 5 and the stationary blade 6. In case of such a jam. the stationary blade mounting i9 may be pivoted away from the rotating blade S merely by manually depressing the ledge 25 of the mounting l! against the tensioned spring 40 to retract the stationary blade 6. After the jam has been cleared. the ledge 25 is released and the spring 40 will return the mounting t9, and the blade clearance, to its proper operating setting.

A further embodiment of my invention is shown in Figures l and 3. As seen therein, the stationary blade 6 which extends substantially the width of the cutter head 1 is supported in a mounting I9 which is in turn positioned over a ixed shaft 22. The blade mounting I9 is capable of rotation around the shaft 22. A ledge extension or boss 25 extends laterally of the stationary blade mounting I9 for substantially the width of the cutter head l. The shaft 22 is mounted in supports 4J, 43 which are ali'ixed to the base supporting plate 30. Also mounted for rotation around shaft 22 and adjacent one end of the cutter head l is a lever 48. A roller follower 5l) is mounted to the upper end of the lever 48 while adjacent the opposite or lower end of the lever 48 is an arm extension SZ of the lever 48. The extension arm 52 lies immediately above the ledge extension 25 of the stationary blade mounting 19. Arr adjusting screw 35 is threaded through the extension arm 52 of the lever 48 to contact the upper surface of the ledge extension or boss 25 of the stationary blade mounting 19. Positioned between thc lower surface of the ledge extension 25 of the blade mounting i9 and the base supporting plate 30 are a series of compression springs 40, I0 which urge upwardly the ledge extension 25 of the blade mounting I9. Lock nut 37 is threaded over the adjusting screw 35 and cooperates with the extension arm S2 of the lever to hold the adjusting screw tinnly in place. A metal reference ring 58 is positioned around the periphery of the cutter head 1 at the end thereof to provide a track for the roller follower 50. The lever and roller follower structure. is duplicated at the opposite end of the shaft 22 to provide accurate and uniform control of the clearance between and across the width of the opposing cutting blades.

In operation, the roller follower S0 is placed against the track 58 and the clearance between the stationary blade 6 and the rotating blades 5, 5 is set by adjusting the position of the adjusting screw 35 against the ledge extension 2S of the blade mounting I9 to rotate the blade mounting i9 around the shaft 22. As mentioned above. the cutter head progressively expands during the cutting extension 2S of the stationary blade mounting to pivot the mounting 19 on the shaft 22 blade 6 backward away from the ing blades 5, S.

My invention also contains another feature which will now be described. From time to time, the cutting edges of thc rotating blades 5, 5 have` to be ground in order to maintain the cutting edges at maximum sharpness. ln grinding the rotating blades 5. S the grinder is set in motion at one side of the blade und travels the width of the blade as it grinds or sharpens the cutting edge of the blade. During the course cf travel of the grinder across the blade, the grinding surface of the grinder is gradually worn down whereby the grinder elettroni n:

error produces or creates a variance of a thousandth of an inch or more in the length of the cutting edge of the blade across the width of the blade. ln order to compensate for this error l have included means for providing angular ndiuslrncnt of the stationary blade mounting t9 along its horizontal axis. As mentioned above, thtsupports 43, 43 for thc stationary shaft 22 nrc affixed to the base support plate 30. The plate 45 is in turn atlxed to n table support 60 by bolts 62 which extend through slots 64 of the base support 30 formed at each end of the support 30. By loosening .thc bolts 62, the plate lll) and the stationary blade mounting 19 al'lxcd to the blade 45 may bc moved angularlyg backward or forward on the table 60 to set the stationary blade 6 ut an angle desired with respect to the cutting edges of thc rotatable blades 5, 5.

Still another embodiment of my invention appears in Figure 4 of the drawing. As seen therein, the stationary blade 6 is supported in a mounting 67 which is in turn positioned over fixed shaft 22. The stationary blade mounting 67 is capable of pivoting around the fixed shaft 22. As with the embodiment of Figures l and 3, a roller follower S0 is provided and follows n metal reference ring 58 positioned around the periphery of the cutter hcnd l. ln this embodiment'. the roller follower 50 is mounted on the frec end of a spring-loaded plunger 69 which is inserted within n strain gauge detector S. A micrometer 72 is provided for adjusting the signal voltage of the detector. The strain gauge detector is mounted upon n support panel 7l which is part =of the stationary blade mounting 67. The detector S is connected by a circuit C with nn electronic servo unit 73 which is in turn connected by a suitable circuit C' to .1 reversible gwr motor 75. The direction of the gear rotation ol' the reversible motor depends upon the signal voltage of the detector S as set up by the position ot' thc plunger 69 within the detector S. A positive signal voltage will rotate the gear in one direction while :r negative signal 'volta'gewill rotate thegenr in the opposite direction. A; pinion-77 mounted on a sli'aft of the motor75 meshes with the teeth cut into the be ul 'i8 of an adjusting screw 19 supported in a frame 81. The adjusting screw 79 is adapted to contact a surface of a ledge or boss 83 extending downwardly from the stationary blade mounting 67. A compressed spring 40 is positioned between the opposite surface of the boss 83 and a haelt stop B5 which spring opposes the pressure applied to the ledge extension 83 by the adjustable screw 79 to firmly bold the stationary blade mounting 61 in place. Tin1 structure described above is duplicated at the opposite end of the cutter head 1 to provide accurate and uniform adjustment and control of tbe clearance between the rotating blades S and the stationary blade 6.

[n operation, to initially set the clearance between the rotating blades 5, 5 and the stationary blade 6, the pinion 71 is disconnected from the reversible gear motor '.'S by disengagiog a clutch (not shown). The udiusting screw is then rotated as desired to move the mounting 61 for the stationary blade 6. The pinion 77 is then connected with the motor 75 by reengsging the clutch member after which the micrometer is Vadjusted to give zero signal voltage for the strain gauge detector. The cutting operation is then commenced. As the cutter bend i and the reference ring 58 expand, for the reason mentioned above, the roller follower Sil will be urged away from the cutter head l to further insert the plunger 69 within the strain gauge detector to alter the signal voltage. Through circuit C the detector transmits a signal of thc change to the reversible gear motor to rotate the pinion 77 of the motor iu a counter-clockwise direction. Through pinion 77 the adjusting screw 79 is rotated in n clockwise direction whereby additional pressure is applied to the surface of the extension ledge 83 of the stationary blade mounting 67 to further compresa the spring 4l) and to rotate the stationary blade mounting 6T in a clockwise direction to move the stationary blade 6 away from the rotating blades 5. S whereby the original set clearance between the opposing blades is maintained.

The embodiment shown in Figure 4 also includes the feature for angulurly adjusting the Stationary blatlt: 6 :u: described with respect to Figures l, 2 and 3.

With the above described apparatus. flock. materia! ol' uniform length (as low as one half millimeter) may be continuously produced without interrupting the operation ot' the cutter to rcadiust blade clearances.

lt is to be understood that: changes :md variations may be made without departing from the spirit and scope of the present invention as defined in the appended claims.

l` claim:

l. A precision liber cutter comprising n rotatable cutter bead, at least one ber cutting blade mounted in the head, a stationary liber cutting blade which cooperates with the blade ot the head to cut the libera. means for feeding a bundle of bcrs or lilamentsto the cutting edge of the stationary blade, n mounting for the stationary blade` means for moving the stationary blade mounting toward and away from the rotatable blade to adjust the clearance between the stationary blade and the rotatable blade, und resilient menns contacting the stationary blade mounting and opposing the adjusting means to hold the stationary blade mounting firmly in the adjusted position. and mcuns lor providing angular adjustment of the stationary blade along the stationary blade axis to further adjust the blade clearance.

l.' A precision liber cutter comprising u rotutuble cutter head. fiber cutting blades mounted in llu: bend. u stationary bcr cutting blade which cooperates with the blades of the head to cut the fibers. means for feeding n bundle of libct's or filaments to the cutting edge of tbc stationary blade` a mounting for the stationary blade. means for supporting the stationary blt-.de mounting, means for moving tbc stationary blade mounting toward and away from the rotatable blades to adjust the clearance beifi :ill

tween the stationary blade and the rotatable blades, se? silient means contacting the stationary blade mounting and opposing the adjusting means to hold the stationary blade mounting rmly in the ndiusted position, and means for providing angular adjustment of the stationary blade along the stationary blade axis to further adjust the blade clearance.

3. A precision fiber cutter comprising a rotatable cutter head. fiber cutting blades mounted in tbe bead, a stationary tibet cutting blade which cooperates with the blader. o! ilu: head to cut the libers, means for feeding a bundle of fibers or filaments to the cutting edge of the stationary blade, a fixed shaft, a mounting for the stationary blade positioned on the shaft, said mounting being capable of pivoting around the shaft, means for adjusting :md controlling the position ofthe stationary blade mounting around the shaft to adjust the clearance between tbc stationary and rotatable blades, a compressed spring contacting the stationary blade mounting and opposing the adjusting means to firmly hold the stationary blade mounting in the adjusted position, and means for providing angular adjustment of the stationary blade :along thc stationary blade axis to further adjust the blade clearance.

4. A precision liber cutter comprising a rotatable cutter head, liber cutting blades mounted in the head. a stationary liber cutting blade which cooperates with the blades of the head to cut the tbcrs, means for feeding a bundle of bers or filaments to the cutting edge of tbe stationary blade. a fixed shaft, n mounting for the stationary blade positioned on the shaft, said mounting being capable of pivoting around the shaft, an extension ledge of tbe stationary blade mounting, an adjusting screw capoble of operating upon one surface of the ledge to adjust und control the position of the stationary blade mounting around the shaft for adjusting the clearance between the stationary and rotatable blades, an anchored compressed spring positioned against the opposite surface of the extension ledge to urge the extension ledge against the adjusting screw, and menus for providing angular adjustment of the stationary blade along the stationnry blade axis to further adjust the blade clearance.

5. A precision tibcr cutter comprising a rotatable cutter head, liber cutting blades mounted in the head, a statonury ber cutting blade extending substantially the width of the cutter head which cooperates with the blades of the head to cut the fibers. means for feeding bundles of tbers Aor lilaments in a side by side relationship, to the cutting edge of the stationary blade, a fixed shaft. a mounting for the stationary blade positioned on the shaft and extending the width of the stationary blade. said mounting being capable ot pivoting around the shaft, an extension ledge of the stationary blade mounting extending the width of the stationary binde mounting, adjusting screws mounted in a bracket extending across the width of the ledge which screws are capable of operating upon one surface of the ledge extension to adjust and control the position of the stationary blade mounting around the shaft for adjusting the clearance between the stationnry and rotatable blades, anchored compressed springs extending across thc width of the ledge and positioned against the opposite surface of the ledge to urge the extension ledge against the adjusting screws. and means for providing angular adjustment of the stationary blade along the stationary blade axis to further adjust the blade clearance.

6. A precision fiber cutter comprising a rotatable cutter head. liber cutting blades mounted in the head, a station- :try liber cutting blade which cooperates with the blades of the head to cut the lbers, means for feeding a bundle of fibers or filaments to tbe cutting edge of the stationary blade, a fixed shaft, a mounting for the stationary blade positioned on the shaft, said mounting being capable of pivoting around the shaft, a lateral ledge extending from the stationary blade mounting, resilient means positioned below and against the bottoni surface of the ledge to urge the stationary blade mounting toward the shaft. a follower mounted on one end of thc lever, said follower adapted to contact the peripbery of the rotatable cutter head and to move the lever in response to any expansion or contraction of the cutter head due to temperature changes of the cutter had, n lateral arm extending from the lever which amt lies immediately above the lateral ledge of the smtionary blade mounting, and means extending from the arm of the lever and adapted to contact and to apply pressure to the top surface of the ledge of the stationery blade mounting in response to movement of the lever. f

7. A precision liber cutter according to claim 6 wherem the follower comprises a roller and the resilient means comprises a compressed spring.

8. A precision fiber cutter according to claim 7 comprising a loclt nut for the adjusting screw to locl` the screw in its adjusted position.

9. A precision fiber cutter according to claim 6 when." in the means extending from the arm extension com prises an adjusting screw.

l0. A precision fiber cutter according to claim 6 comprising a metal reference ring around the cutter head periphery which ring contacts the follower.

l l. A precision fiber cutter comprising n rotatable cutter comprising s rotatable cutter head. fiber cutting blades mounted in the head, a stationary liber cutting blade cxtending substantially the width of the cutter head which blade cooperates with the blades of the cutter head to cut the bers, means for feeding bundles of lbers or filaments in a side by side relationship to the cutting edge of the stationary blade, a fixed shnt't, n mounting for the stationary blade positioned on the shaft and extending the width of the stationary blade, said mounting being capable of pivot ing around the shaft, a lateral ledge extending from the stationary blade mounting for the width of the mounting, anchored compressed springs positioned below the bottom surface and extending the width of the ledge to urge the stationary blade mounting toward the cutter head, tt lever mounted on each end of the lixcd shnh, said levers being adapted to pivot around the shaft. tt roller follower mounted on one end of each lever, said rollers adapted to contact and follow the periphery of the rotatable cutter hettd and to move the levers in response to any expansion 0r contruction of the cutter head duc to temperature changes of the cutter head, a lateral arm extending from each lever which -arms lie immediately above the ledge extensions of thc stationary blade mounting, und an adjusting screw extending through the arm of each lever und adapted to contact and to apply pressure to the ledge of the stationary blade mounting in response to movement of the levers.

l2. A precision liber cutter according to claim ll comprising metal reference rings around euch end of the pe riphery of the cutter head followers.

I3. A precision liber cutter comprising a rotatable cutler head. fiber cutting blades mounted in the heed, a stationary ber cutting binde which cooperates with the blades of the bend to cut thc Ebcrs. means for feeding a'bundle of fibers or filaments to the` cutting edge ol the stationary blade. a fixed shalt', a mounting for the stationary blade positioned on the shaft. said mounting being capable of pivoting around the shaft, u ledge extending from the stationary binde mounting, resilient means positioned against one surface of the ledge to urge the stntionary blade mounting toward the cutter head, u strain gouge detector adjacent the cutter head supported by the mounting for the stationary blade, a micrometer adjusting means connected with the signal voltage of the detector. inserted within one end of the ter head for altering the signet voltage, a follower mounted on the free end of thc plunger, said follower adapted to contact and follow the periphery of the rotatable cutn spring loaded plunger detector adjacent the cut` which rings contact the roller detector for adjusting thc tit t Ier head. un electronic servo unit which is actuated by the plunger of tite strain gauge detector, a reversible gear,

motor which is actuated hy the electronic servo unit, a-

revcrslble gear connected with the gear motor, means controlled by the reversible gear which means contacts and rtppiies pressure on the surface of the ledge opposite that surface contacting the resilient means to move the stntionary blade mounting toward or away from the cutter head in response to a change of position of the spring loaded plunger.

t4. A precision liber cutter according to claim t3 wherein the follower `comprises a roller and the resilient means comprises a compressed spring.

l5. A precision liber cutter according to claim I3 wherein the means controlled by the reversible gear comprises un adjusting screw.

A precision lbcr cutter according to claim t4 comprtstng a nl the cutter head which ring contacts the roller follower.

t7. A precision liber cutter comprising a rotatable cuttcr head. fiber cutting blades mounted in the head. a stationary blade extending the width ofthe cutter heud which blade cooperates with the blades of the head to cut the fibers, means for feeding bundles of libcrs or filaments in u side by side relationship to the cutting edge ofthe stationary blade. a lixcd shaft, a mounting for the stationary blade positioned on thc shaft and extending the width of the stationery blade, said mounting being capable of pivotng around the shaft, u

detector supported by the stationary blade mounttng adjacent cach end of the cutter head. a micrometer adjusting means connected with each detector for adjusting the signal voltage of the detectors. a spring loaded plunger inserted within each strain gauge detector for altering the signal voltngc, a roller follower mounted on the free rnd of cach plunger. said roller followers adapted to contact and follow thc periphery of the rotatable cutter heed. an electronic servo unit for each strain gauge detector which units nrc actuated by the detectors. a reversible motor lor each servo unit which motors urc actuated by thc servo units. a reversible gear for cach gear motor, an adjusting screw for erich reversible gear which screws are actuated by the gern-s und which nre adapted ro contact und to apply pressure :tgainsr the ment of the spring loaded plungcrs.

A precision fiber cutter according to cluin't t7 com References Cited in the tile of this patent UNlTED STATES PATENTS 583,l4l Dillon May 25, i897 2.2l7.766 Nei Oct. l5, l940 FOREIGN PATENTS 492,947 Great Britain Sept. 29, l938 

